I picked up a pair of 620ml "Redshift" bottles ca a year ago, they had a "silicon dioxide coating" equvialent of brandname "Purist" bottles.
They keep the water tasting good but the cap may be a bit a leaky if they lay flat. However i cant find them an Ali anymore, and iv'e been looking for other bottles with silicon dioxide, so i hope there is someone out there that kan give us a pointer to a good bottle.